1. Field of the Invention
The present invention relates generally to recording and reproducing apparatus and, more particularly, is directed to a data recording and reproducing apparatus suitable for recording, for example, audio data, video data or computer data on a record medium such as a disk.
2. Description of the Prior Art
Generally, when data is recorded on a record medium, two modes, i.e., a consecutive processing mode and, an alternate processing mode may be available. The term consecutive processing mode is used in this specification to the recording mode for recording digitized, analog information such as audio data, video data or the like, whereas the term "alternate processing mode" is used in this specification to refer to the recording of intermittent, digital data, such as during the storage of computer data.
A real time property is a very important factor for audio data, video data and so on used in the consecutive processing mode. In the case of audio data and video data or the like, the digitized, analog date have a correlation with each other to each other so that they can therefore be error-compensated, thus avoiding an influence of error to some extent.
In the alternate processing mode, if a sector of a hard disk or a magneto-optical disk or the like, in which data is to be written when it is shipped, is found to be defective due to scratches or the like, that defective sector is marked with a failure sector mark and is made useless. Then, corresponding data is written in an alternate sector prepared as a reserve sector. Alternatively, in the read-after-write mode, if an error rate is beyond a standard one, then data is to be written in the alternate sector.
Although the above-mentioned consecutive processing mode is advantageous in real time property, error of more than a certain error rate can not be processed. Thus, the consecutive processing mode is not so reliable. Further, although the alternate processing mode is very reliable, it has a problem of poor real time property.